MI wsfb Xorg driver is working on hpcarm, hpcmips, hpcsh, and
dreamcast

etc. so no reason not on m68k :-)
The only remaining problem is keymap, but Xorg's sources are
too complicated to track how keycode and keymaps are processed...
(It heavily depends on AT/XT keyboard)

All the voodoo we need to care about is in the xf86-input-keyboard
driver, see xsrc/external/mit/xf86-input-keyboard/dist/src/
bsd_KbdMap.c, there's a bunch of tables which map Sun, ADB etc.
scancodes to AT-ish ones used by Xorg. Add a table for HIL, add a
case: for it to KbdGetMapping and that's pretty much it. Alternatively
you could let the HIL keyboard driver produce USB scancodes in event
mode and change its type to WSKBD_TYPE_USB - that wouldn't need any
changes in X.
Eventually I'll do that with ADB and Sun keyboard drivers so they can
live on the same mux with USB keypads and the like in event mode too.
I'd do the above myself but unfortunately my 345 is still on the other
side of the atlantic.